This book focuses on the characteristics of ZnO films fabricated by AP-MOCVD. ZnO shows high optical transmittance (greater than 85%) and electrical conductivity (resistivity about 10-4 -cm) for the transparent electrode. Particularly, compared to ITO, the material resource of ZnO is ample and no after-use worry concerned with the environmental protection is required. So this thesis has completed that the characterizations of undoped, n- and p-type ZnO semiconductors fabricated by AP-MOCVD.